Tube-splicing mandrel



Febo 8 7 Filed Sept. 1'7. 1925 ATTORNEY Patented Feb. 8, 1927.

` Unirsnsreres eretta.

ROBERT J. MILLGAN, 0F AKRON', OHIO, ASSIGNOR TO THE GOODYEAR TIRE @c RUBBER COMPANY, 0F AKRON, OHIO, A CORPORATON OF (3l-HO.`

Application mea september 17, 1925. serial No'. 56,9452..

Another object'of my invention is to pro@ vide a heat-insulating means for a tube splicingmandrel which serves an additional purpose of supplementing the surface of the mandrel upon which the tube is spliced.

In the manufacture ofginner tubes forA pneumatic tires, layers of vrubber stoel;l are applied Vto a straight cylindrical mandrel vof proper ylength and the mandrel with its sheath of rubber thereon is subsequently placed within a heater to vulcanize the tubes. After the vulcanizing process is completed, the rubber' sheath, in the form of a tube lis stripped from the mandrel and, in order toA shape-it intov annular form, the ends thereof must be spliced together. This operation is accomplished by applying suitable cement or otherv vulcanizable material to the ends or the tube, which have been properly skived in preparation therefor, slightly telescoping one end within the other, and ysubjecting them to heat to vulcanize-the cement, therebycausing a firm union between the ends of the tube. 1

. Because of the fact that great numbers of inner tubes are manufactured, it `is evident that any saving in the time-required to splice the ends effects a material saving in manufacturing costs.

A Well known device which has been employed in splicing tubes consists lin a cylindrical mandrel having a steam or otherv luid heating chamber and formed with a longitudinal slot therein7 through which a tube having its ends secured together kluy-means of uncured cement may be inserted. o Heatinsulating members are provided whichengage the inner walls of the cylindrical mandrel to protect theiportion of the tube on the inside of the mandrel from the heating chamber. l

lAfter the tube is inserted 'through the slot in the mandrel, a gate member pivoted upon the mandrel is adapted to be manually moved to close theslot in .order to form complete cylinder. The portion of the tube which has Abeen spliced together is then. i drawn over the circular mandrel anda vsegf mental .heating annulus provided ivit'h a pneumatic heating padfis secured about the mandrel in circumferential relation over the joined ends of the tube. These cemented endsV are then vulcanized together bythe heat fromV the chamber of the mandrel and` from the .segmental heating annulus.

t' is the principal aim of my invention to dispense with the hingedl gate member and toV provide aV novel `closing device for a slotformed in a mandrel similar 4to' ythe mandrel previously described. With this vvend in View, Ifhave provided a Vh-eat-insulating apparatus composed of two .complemental cylindricall members which `it into the gman-l drel, one of which members isv formed with a key ot' equal width with the slot, in the mandrel adapted to'be inserted into the slot to close it. rlhe louter portion .of the key member is disposed flush with ,the outer` surface Yof the mandrel, By utilization ,of .a member yof this nature, the number .of operations involved in properly positioning .the cemented ends of the ,tube upon the mandrel is reduced. K4Also the number of parts required for the splicing device is reduced .and the manufacture thereof materially simplified. This Vreduction ot" time required to splice the ends of the tube and the `simplification ofthe structurall elements ofthe device' lare particularly important advantages in factories where thousands of tubes are spliced daily.v

For a better understanding of my invention, .reference may now be Vhad to the ac# vcom-panying drawings forming a part `of this sembleddev-ice, the plane of the 'section be- ,a

ing taken substantially centrally thereof.

In practicing my invention I provide .a

vcylindricalhollow metal i-nandrelr l()v which ico is formed with a relatively small hollow eX- tension l1. At the side of the mandrel, subv be inserted Withiinthe mandrel.

stantially opposite that from Which the eX- tension projects, a longitudinal slot 12 is formed which permits an inner tube 13 to The extension 11 formed on the mandrel is Vprovided with threaded openings 14 which are adapted to communicate with a source of heating fluid, such as steam or hot Water,

Which is circulated Within a heating chamber 15 provided in the cylindrical mandrel.

In order to prevent the inner tube fromk Y directly engaging the inner Walls of the heating chamber 15, tW'o semi-cylindrical insulating members 16 and 17 are vprovided `which are adapted to be inserted Within the ymandrel 10 Vand are formed with tapering may be cast integrally with the lmember 16 or it may be separately formed and secured in proper position by any suitable fastening means.` It will be observed that the end of the key member is provided With a tapered or reduced portion 21 Which serves to facilitate the insertion of the member 16 Within the mandrel. Also the outer portion ofthe key member 20V is slightly enlarged, as indicated at 22'and the slot 12 is correspondingly enlarged at 23 in order to prevent movement of the member 16 toward the axis of the mandrel and to maintain the outer surface of the key member flush With the outer surface of the mandrel. VThe other heat-insulating member 17 is disposed concentrically with respect to the inner Wall of vthe heating chamber 15 and in contact therewith. t is necessary that the member 17 be n permanently secured in proper position Within the mandrel by means of suitable conneet-ing device or by Welding, in order to prevent it'v from being displacedvvhen r-emoving an inner tube from the mandrel, and

` to serve as a guide for the member 16.

In the operation of the device embodying my invention, after the member17 ,is secured in proper position Within the cylin` drical mandrel and an inner tube 13, Which has its ends slightly telescoped, as indicated at 24, and coated With cement preparatory tol vulcanization, is'inserted through the slot 12,

the joined ends 24 being spaced froml the mandrel. At this Ypoint in the operation, the

vmember" lis inserted in the mandrel, the

vexpense reduction in the spirit of myfinvention or from "the appended claims.V

key 2O closing the slot 12. The inner tube is then drawn telescopically over the outer surface ofthe mandrel until the joinedends 24 arein contact with Jthe outer surface ofl the mandrel approximately vcentrally there.- of. Pressure is applied to the tubeV against the mandrelby means of an annular member -25 having a pneumatic pad 26 disposed other to be spliced.v v

It will'be apparent from the foregoing description that my invention provides a -dcci ded improvement over the devices formerly employed in splicing tubes and that, by the utilization of my invention, speed of production may be incr-eased While the reduction of the number of parts required in constructing the device affords'a corresponding manufacturing cost thereof.

Although I have illustrated but one form Which my invention `may` assume and have f described in detail 'but a single application thereof, it Will be apparent to those `skilled in the art that it is not so limited but that vagv rious minor modificationsand changes may be made therein Without departingl from the the scope Vof What I claim is: Y u Y 1. A tube splicing device comprising an annular mandrel havinga slot therein and a heat 'insulating member adapted *to be inserted Within the mandrehsaid member being provid-ed with Vmeans secured thereto for closing the slot.- Y v f f 2. A tube splicing device comprising an annular mandrel provided with a slot, a semi-cylindrical member adapted to be inserted in the mandrel, and a key Vmember formed on the member adapted to be disy K posed in the slot.

3. A tubeV splicing device comprising an annular mandrel provided with arslotted portion and with a heating chamber therein, and heat insulating means including two semi-cylindrical members adapted to beeinserted Within the mandrel, one of the members being formed with means for closing.

the slotted portion of the mandrel Hush with the exterior surface thereof. Y

l-A heat insulating member 'adapted tobe inserted in a tube splicing device comprising a semi-cylindrical portion, a tapered portion and a rib extending longitudinallyV on the outer surface of theV cylindrical portion.

In Witness whereof, I have hereunto signed my f name.

nonni-ir J. MILLIGAN. 

